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The following parameters can be defined for the sheathing applied to the sides of a shear wall in Wall Input View.
Sheathing Material - you must select a material from list of materials in design code tables. Changing the material refreshes the choices for all other inputs in the dialog.
Sheathing Thickness - The program provides a list of standard plywood thicknesses from the design code tables. You can enter a different thickness yourself and the program will design for the closest thickness less than the one you selected, so this input can be considered a minimum thickness. Plywood is not manufactured in other thicknesses, so there is little need to enter a thickness other than one in the list.
Sheathing thickness can be unknown. Changing the thickness refreshes the choices for span rating and nail size.
Orientation of long side of panel - For structural wood panels, this is vertical or horizontal. The orientation primarily affects wind component and cladding out-of-plane bending design, but there are certain exceptions for shear wall strengths that depend on orientation. For lumber sheathing, the orientation can also be diagonal or double-diagonal, and orientation affects shear strength.
Plies or Marking – The name of this field changes depending on the material selected; plies for plywood, panel marking for OSB. It affects the design strengths for from tables 9.3A-C, affecting the C&C resistance, shear stiffness for deflection, and the panel bending component of shear wall strength.
OSB - Construction Sheathing OSB, manufactured in accordance with CSA Standard O325. You must first select a panel marking in order to have choices for sheathing thickness and nail sizes, which corresponds to an equivalent panel thickness used in determining the shear strength (see CSA O86 Table A9.2.2A). The actual panel thickness may also be specified by the user – it is used to determine the depth of nail penetration for lateral nail strength for shear design and withdrawal strength for C&C design.
OSB is not allowed when wet service conditions are selected in the Design Settings.
Blocking - This check box indicates whether the sheathing panel edges on the selected side or sides are nailed to blocking. Note that vertically oriented panels are still considered to be unblocked unless they are staggered such that there are horizontal seams to be blocked.
An unblocked factor is applied to shear strength and deflection calculations for unblocked structural wood panels. Gypsum wallboard has different shear design values depending on whether it is blocked or unblocked.